Since rodents and particularly mice tend to move adjacent to or in proximity to the baseboards or bases of walls and are attracted to tunnel shaped entrances, such as the proverbial "mousehole", a trap which can be readily paced in juxtaposition to a wall or baseboard with tunnel-type portals permitting access to a plurality of rodents is highly desirable.
Tunnel shaped traps have been proposed in the past, for instance in U.S. Pat. Nos. 2,573,228 to Slauth; 4,103,448 to Souza; and 4,554,758 to Molloy.
Slauth's cylindrical tunnel trap is a baitless animal and rodent trap having an opening at one end with closure means; and a closed perforated closure at the other. A bent rod is associated with a coil spring and the open end is closed by its closure when the animal or rodent engages a panel which pushes the rod.
Souza's tunnel animal trap is adapted to trap a plurality of animals while automatically resetting itself. It has a single entrance and when an animal passes over a tilted floor it is trapped in a container section as the tilted floor returns to its original position to permit trapping another animal.
Molloy's tunnel trap also lures animals which hide in tunnels or other hollow areas. When the animal is in the housing of the trap and mounts a switch, electricity is supplied leading a door to close preventing escape of the animal.
In Pairo U.S. Pat. No. 1,850,634, a trap in the shape of a "T" is described. However, the rats trapped therein do not enter into a portion of the trap which can be placed in juxtaposition to a wall. Rather, the rats enter into the leg portion in which the bait is placed on a treadle which when tripped causes a latch to be pulled downward through rods and leads to disengagement of a bolt from a lug and moves a bar and a closure to close the front end of the trap. As the rats pass over the treadle they enter into the head of the T wherein they are retained without access to the leg portion while the downward movement of the treadle resets the trap.
Other devices adapted for trapping a plurality of animals are described in U.S. Pat. Nos. 1,524,692 to Dick and 2,524,423 to Buford.
Dick describes an animal trap of wire mesh with a top having a cross shape when open, a bottom and multiple entrances permitting entry of many animals. The entrances are closed by closures including a frame carrying wire mesh and hinged to the top. The closure is effected by means of a trigger arm and trip arm.
In an embodiment of Buford's disclosure a plurality of animals, particularly small ones such as rodents, enter an enclosure at any of three entrances and travel toward the bait in a small enclosure. When an animal moves into a fourth passage it is prevented from leaving by passing over a tiltable floor which causes a mechanism to close with the animal trapped in a secondary closure. The tiltable floor returns to its original position to permit trapping another animal which walks into it.
Rodent traps which are rather complex in structure and operation have also been suggested, for instance in U.S. Pat. Nos. 2,574,780 to Giacoletto and 4,418,493 to Jordan.
Giacoletto describes a tower trap with multiple means for catching rodents. The trapping technique is effected when a rodent reaches for bait and moves a bait arm, ultimately causing a gate to close.
Jordan describes a modular trap which is versatile for catching small or large animals including a capture module which provides bagging means. Animals may enter the trap through entry ports, which due to the modular shape of the trap are perpendicular to a wall when the trap lies against the wall. There is no provision for closing the entry ports.
Some traps are specifically designed against the safety of trapped animals, for instance those described in U.S. Pat. Nos. 2,962,836 to Hughes and 4,787,170 to Kingsbury et al.
In Hughes' trap captured rodents or large insects are retained on an adhesive sheet after they enter a hood structure through an opening. There is no provision for closing the openings but the adhesively trapped animals are not able to roam.
In the trap of Kingbury et al. a rodent is attracted by a bait scent to push open a door which pivots closed behind it. The trap has a low oxygen content and orifices in the door are too small to admit enough air to keep the rodent alive.